Polychromos colour pencil
152 middle phthalo blue
Pitt Pastel pencil
light ultramarine
cobalt blue
helioblue reddish
dark indigo
247 indanthrene blue
246 Prussian blue
Albrecht Dürer watercolour pencil
Prussian blue
indanthrene blue
Goldfaber colour pencil
ultramarine
blue violet
light blue
phthalo blue
skyblue
light phthalo blue